JP2006102160A - Blood pressure measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blood pressure measuring device capable of measuring a blood pressure highly precisely while stabilizing a pulse wave even though distances between a site to be measured of a subject, and a light emitting element and a light receiving element are changed due to the movement of the subject or the disturbance such as pulsation in a blood pressure measurement using the measurement of the pulse wave by light. <P>SOLUTION: This blood pressure measuring device has the light receiving element receiving the light reflected by the face of the light emitting element side of the expandable member of a cuff of the light irradiated toward the expandable member from the cuff of the light emitting element, the output signal of the receiving element is processed as a noise component along with a pulse wave signal having measured the subject, thereby the noise component due to the movement of the subject and the disturbance such as the pulsation can be reduced, the blood pressure measuring device capable of always measuring the blood pressure highly precisely while stabilizing the pulse wave of the subject even though the device can not be completely secured the subject can be provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a blood pressure measurement device using a cuff that presses a part of a subject.

  A conventional blood pressure measurement device is mounted so that a rectangular and flat cuff is wrapped around a portion to be measured, and after the air is supplied to the cuff and compressed with a pressure that stops blood flow in the subject, the cuff is Changes in the pulmonary arterial wave in the subject in the process of decreasing the pressure to press the subject are measured, and blood pressure is measured from the pressure of the subject by the cuff and changes in the pulsation waveform. Here, as a method of measuring the pulsation waveform with the cuff, conventionally, a method of measuring the pulsation of the blood flow transmitted to the cuff by a change in pressure in the cuff has been common.

  Recently, as a method for easily detecting pulse waves with a smaller device and measuring blood pressure with high accuracy, the device is attached to the peripheral part of the subject such as the auricle and the subject is equipped with a light emitting element provided in the device. A method has been developed in which scattered light obtained by irradiating the irradiated light scattered by the blood vessel of the subject or blood cells in the blood vessel is received by a light receiving element provided in the apparatus, and a pulse wave is detected from the received scattered light. . (For example, refer to Patent Document 1.) This is calculated from the amount of received light of scattered light of infrared light and visible light radiated into the living body such as pulse, pulse wave, electrocardiogram, body temperature, arterial oxygen saturation, and blood pressure. I can do it.

  Moreover, as an apparatus to be worn on the auricle, there is an emergency information apparatus that includes wireless communication means and includes an arterial blood oxygen saturation sensor, a body temperature sensor, an electrocardiogram sensor, and a pulse wave sensor (for example, see Patent Document 2) .) In this device, the sensor portion is inserted into the ear canal, and the data communication unit is used as a means for fixing to the ear.

  On the other hand, regarding blood pressure measurement, a blood pressure measurement device that measures a pulsation waveform of a blood vessel is aligned with a blood pressure measurement device that uses other methods such as a cuff vibration method or a volume compensation method (for example, see Non-Patent Document 1). Recognized as a powerful blood pressure measurement method.

In the present application, the name of the pinna is based on Non-Patent Document 2, and the name of the pinna cartilage is based on Non-Patent Document 3.
JP-A-9-128203 JP-A-11-128174 Kenichi Yamakoshi, Tatsuo Togawa, “Biological Sensors and Measuring Devices”, MM Society of Japan / ME Textbook Series A-1, pages 39-52 Sobotta Illustrated Human Anatomy Volume 1 (Translation by Michio Okamoto), p. 126, Medical School, issued October 1, 1996 Sobotta Illustrated Human Anatomy Volume 1 (Translation by Michio Okamoto), p. 127, Medical School, issued October 1, 1996

  In blood pressure measurement using measurement of pulse waves by light as described above, it is necessary to detect a weak signal with high accuracy. However, it is difficult to completely fix the conventional device even if it is attached to the peripheral part of the subject such as the auricle, and disturbances such as movement and pulsation of the subject become noise components of the signal output from the light receiving element, There has been a problem that an error is caused in the measurement value of the blood pressure measurement, and the blood pressure cannot be measured stably with high accuracy in the pulse wave.

  Therefore, the present invention solves the above-described problems in the conventional example, and even if the distance between the measured portion of the subject and the light emitting element and the light receiving element is changed due to disturbance such as movement or pulsation of the subject, the pulse It is an object of the present invention to provide a blood pressure measurement device that can stably measure blood pressure with high accuracy.

  In order to solve the above problems, the first invention of the present application is that the light emitting element irradiates light from the inside of the cuff to the outside, in particular, the subject, and the light scattered by the subject is received by the light receiving element. The light irradiated from the light emitting element is reflected by the light receiving element side surface of the cuff elastic member and received by another light receiving element.

  Specifically, the first invention of the present application irradiates light to the outside of the cuff through a cuff partly covered with a light transmissive elastic member and a light transmissive part of the elastic member. A first light-receiving element that receives light scattered outside from the cuff through the first light-emitting element that performs light transmission of the telescopic member. And a second light receiving element that receives, in the cuff, light reflected from the surface of the telescopic member on the first light emitting element side, irradiated with the light from the first light emitting element. It is.

  The signal output from the first light receiving element and the signal output from the second light receiving element contain the same noise component due to disturbance such as movement of the subject and pulsation. The second light receiving element receives light reflected by the surface of the telescopic member on the first light emitting element side, and the movement of the subject, pulsation, etc. The noise component due to the external disturbance is measured. Therefore, if the signal output from the first light receiving element, which is a pulse wave signal of the subject, and the signal output from the second light receiving element, which is a noise component, are signal-processed, the noise component can be reduced.

  The first invention of the present application may further include a difference calculating means for calculating a difference between a signal output from the first light receiving element and a signal output from the second light receiving element. From the signal output from the first light receiving element by calculating the difference between the signal output from the first light receiving element which is a pulse wave signal of the subject and the signal output from the second light receiving element which is a noise component Noise components can be reduced.

  In the first invention of the present application, it is preferable that the second light receiving element has a light shielding means for preventing the light scattered outside. The light shielding means prevents the second light receiving element from receiving the light scattered outside, and from the signal output from the second light receiving element, the first light emitting element side of the telescopic member A signal due to light other than the light reflected by the surface can be reduced. Thereby, it is possible to accurately extract a noise component due to disturbance such as movement of the subject and pulsation.

  Therefore, the blood pressure measurement device according to the first invention of the present application can reduce noise components due to disturbances such as movement and pulsation of the subject from the pulse wave signal of the subject output from the first light receiving element. Even if the peripheral part of the subject cannot be completely fixed, the pulse wave of the subject can be constantly measured with high accuracy and stability.

  In order to solve the above problems, the second invention of the present application is that the light emitting element irradiates light from the inside of the cuff to the outside, in particular, the subject, and the light scattered by the subject is received by the light receiving element. The light irradiated from the inside of the cuff of the light emitting element toward the expansion / contraction member is received by the other light receiving elements as the light reflected by the light emitting element side surface of the expansion / contraction member of the cuff.

  Specifically, the second invention of the present application irradiates light to the outside of the cuff through a cuff partly covered with a light transmissive elastic member and a light transmissive part of the elastic member. A first light-receiving element that receives light scattered outside from the cuff through the first light-emitting element that performs light transmission of the telescopic member. And a second light emitting element that irradiates light toward the elastic member in the cuff, and light irradiated by the second light emitting element is reflected by the surface of the elastic member on the second light emitting element side. And a third light receiving element that receives the light in the cuff.

  The signal output from the first light receiving element and the signal output from the third light receiving element contain the same noise component due to disturbances such as movement and pulsation of the subject. The third light receiving element receives light reflected by the surface of the telescopic member on the first light emitting element side, and the movement of the subject, pulsation, etc. The noise component due to the external disturbance is measured. Accordingly, if the signal output from the first light receiving element, which is a pulse wave signal of the subject, and the signal output from the third light receiving element, which is a noise component, are signal-processed, the noise component can be reduced.

  The second invention of the present application may further comprise a difference calculating means for calculating a difference between a signal output from the first light receiving element and a signal output from the third light receiving element. From the signal output from the first light receiving element by calculating the difference between the signal output from the first light receiving element which is a pulse wave signal of the subject and the signal output from the third light receiving element which is a noise component Noise components can be reduced.

  In the second invention of the present application, it is preferable that the third light receiving element has a light shielding means for preventing the light scattered outside. The light shielding means prevents the third light receiving element from receiving light scattered outside, and from the signal output from the third light receiving element, the second light emitting element side of the telescopic member A signal due to light other than the light reflected by the surface can be reduced. Thereby, it is possible to accurately extract a noise component due to disturbance such as movement of the subject and pulsation.

  In the second invention of the present application, the light emitted from the first light emitting element may be light having a wavelength different from that of the light emitted from the second light emitting element. Two different wavelengths are used for the light emitted from the first light emitting element and the light emitted from the second light emitting element, and only the wavelength of the light emitted from the second light emitting element to the third light receiving element is used. By setting the light receiving device to receive light, the third light receiving device emits light with a wavelength of light emitted from the second light emitting device even when light scattered outside is incident on the third light receiving device. And does not detect the scattered light of a different wavelength. Therefore, it is possible to reduce a signal due to light other than light reflected by a part of the telescopic member on the second light emitting element side from the signal output from the third light receiving element. Thereby, it is possible to accurately extract a noise component due to disturbance such as movement of the subject and pulsation. Further, by setting the first light receiving element to receive only the wavelength of light emitted by the first light emitting element, even when the reflected light is incident on the first light receiving element. The first light receiving element does not detect the reflected light of different wavelengths. Thereby, the signal by light other than the light scattered outside from the signal which said 1st light receiving element outputs can be reduced.

  Therefore, the blood pressure measurement apparatus according to the second invention of the present application can reduce noise components due to disturbances such as movement and pulsation of the subject from the pulse wave signal of the subject output from the first light receiving element. Even if the peripheral part of the subject cannot be completely fixed, the pulse wave of the subject can be constantly measured with high accuracy and stability.

  In order to solve the above-mentioned problems, the third invention of the present application is that the light emitting element emits light from the inside of the cuff to the outside, particularly, the subject, and the light transmitted through the subject is received by the light receiving element outside the cuff. At the same time, the light irradiated by the light emitting element is reflected by the light receiving element inside the cuff to receive the light reflected by the light emitting element side surface of the expansion member of the cuff.

  Specifically, the third invention of the present application irradiates light to the outside of the cuff partly through a cuff partly covered with a light transmissive elastic member and the light transmissive part of the elastic member. A first light emitting element, a fourth light receiving element that receives light emitted from the first light emitting element outside the cuff through the light transmissive portion of the expansion member, and the first light receiving element. A blood pressure measurement apparatus comprising: a second light receiving element that receives, in the cuff, light reflected from a surface of the expandable member on the first light emitting element side.

  The signal output from the fourth light receiving element and the signal output from the second light receiving element contain the same noise component due to disturbance such as movement of the subject and pulsation. The second light receiving element receives light reflected by the surface of the telescopic member on the first light emitting element side, and the movement of the subject, pulsation, etc. The noise component due to the external disturbance is measured. Accordingly, if the signal output from the fourth light receiving element, which is a pulse wave signal of the subject, and the signal output from the second light receiving element, which is a noise component, are signal-processed, the noise component can be reduced.

  The third invention of the present application may further comprise a difference calculating means for calculating a difference between a signal output from the fourth light receiving element and a signal output from the second light receiving element. From the signal output from the fourth light receiving element by calculating a difference between the signal output from the fourth light receiving element which is a pulse wave signal of the subject and the signal output from the second light receiving element which is a noise component. Noise components can be reduced.

  Therefore, the blood pressure measurement device according to the third invention of the present application can reduce noise components due to disturbance such as movement and pulsation of the subject from the pulse wave signal of the subject output from the fourth light receiving element. Even if the peripheral part of the subject cannot be completely fixed, the pulse wave of the subject can be constantly measured with high accuracy and stability.

  In order to solve the above-described problem, the fourth invention of the present application is that a light emitting element outside the cuff irradiates the subject with light and the light transmitted through the subject is received by the light receiving element inside the cuff. The light irradiated from the internal light emitting element toward the expansion / contraction member is reflected by the light receiving element side surface of the cuff expansion / contraction member and received by another light receiving element.

  Specifically, the fourth invention of the present application includes a cuff partially covered with a light-transmitting elastic member, a third light emitting element that emits light from the outside of the cuff, and the elastic member. A fifth light receiving element that receives light emitted from the third light emitting element in the cuff through a light-transmitting portion, and a second light that irradiates light toward the expandable member in the cuff. A blood pressure comprising: a light-emitting element; and a third light-receiving element that receives, in the cuff, light reflected by the second light-emitting element side surface of the elastic member. It is a measuring device.

  The signal output from the fifth light receiving element and the signal output from the third light receiving element contain the same noise component due to disturbances such as movement and pulsation of the subject. The third light receiving element receives the light reflected by the second light emitting element on the second light emitting element side surface of the telescopic member, and the movement of the subject, pulsation, etc. The noise component due to disturbance will be measured. Accordingly, if the signal output from the fifth light receiving element, which is a pulse wave signal of the subject, and the signal output from the third light receiving element, which is a noise component, are signal-processed, the noise component can be reduced.

  The fourth invention of the present application may further comprise a difference calculating means for calculating a difference between a signal output from the fifth light receiving element and a signal output from the third light receiving element. From the signal output from the fifth light receiving element by calculating a difference between the signal output from the fifth light receiving element which is a pulse wave signal of the subject and the signal output from the third light receiving element which is a noise component. Noise components can be reduced.

  In the fourth invention of the present application, it is preferable that the third light receiving element has a light blocking means for preventing light received by the third light emitting element. The light shielding means prevents the third light receiving element from receiving light scattered outside, and from the signal output from the third light receiving element, the second light emitting element side of the telescopic member A signal due to light other than the light reflected by the surface can be reduced. Thereby, it is possible to accurately extract a noise component due to disturbance such as movement of the subject and pulsation.

  In the fourth invention of the present application, the light emitted from the third light emitting element may be light having a wavelength different from that of the light emitted from the second light emitting element. Two different wavelengths are used for the light emitted from the third light emitting element and the light emitted from the second light emitting element, and only the wavelength of the light emitted from the second light emitting element to the third light receiving element is used. By setting to receive light, even when light transmitted through the subject is incident on the third light receiving element, the third light receiving element has a wavelength of light emitted by the second light emitting element. The light transmitted through the subject having a wavelength different from the above is not detected. Therefore, it is possible to reduce a signal due to light other than light reflected from the surface of the elastic member on the second light emitting element side from the signal output from the third light receiving element. Thereby, it is possible to accurately extract a noise component due to disturbance such as movement of the subject and pulsation. Further, by setting the fifth light receiving element so as to receive only the wavelength of light emitted by the third light emitting element, even when the reflected light is incident on the fifth light receiving element. The fifth light receiving element does not detect the reflected light of different wavelengths. Thereby, it is possible to reduce a signal due to light other than the light transmitted through the subject from the signal output from the fifth light receiving element.

  Therefore, the blood pressure measurement device according to the fourth invention of the present application can reduce a noise component due to disturbance such as movement and pulsation of the subject from the pulse wave signal of the subject output from the fifth light receiving element. Even if the peripheral part of the subject cannot be completely fixed, the pulse wave of the subject can be constantly measured with high accuracy and stability.

  According to the invention of the present application, the light output from the cuff of the light emitting element toward the expansion / contraction member is provided with a light receiving element that receives light reflected by the light emitting element side surface of the expansion / contraction member of the cuff, and a signal output from the light receiving element Signal processing together with the pulse wave signal measured from the subject as a noise component, noise components due to disturbances such as movement and pulsation of the subject can be reduced and can be completely fixed to the peripheral part of the subject. It is possible to provide a blood pressure measurement device that can stably measure the pulse wave of the subject with high accuracy and stability at all times.

Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment.
(Embodiment 1)

  FIG. 1 is a schematic view showing an embodiment of a blood pressure measurement device according to the first embodiment of the present invention. The blood pressure measurement device 901 includes the telescopic member 10, a housing 12 a, a light emitting element 111, a light receiving element 121, and a light receiving element 122. The elastic member 10 and the housing 12 a constitute a cuff 11.

  The light emitting element 111, the light receiving element 121, and the light receiving element 122 are installed in the housing 12a of the blood pressure measurement device 901 of the present embodiment. The material of the housing 12a is not particularly limited. However, since it is attached to the peripheral part of the subject as a blood pressure measuring device and pressure by air is applied, it is lightweight, and is preferably a plastic such as plastic, aluminum, or stainless steel that does not deform with pressure. .

  The light emitting element 111 irradiates the outside of the cuff 11 with irradiation light A for measuring the blood vessel pulsation of the subject.

  The scattered light B is generated by the absorption and scattering of the irradiation light A by the pulse wave of the blood vessel in the subject. More specifically, the irradiation light A is absorbed and scattered by the increase / decrease of blood in the portion to be measured accompanying the pulsation of the blood vessel of the subject, that is, the amount of hemoglobin in the blood, and becomes the scattered light B. As the irradiation light A, light having a wavelength of 300 nm to 1500 nm can be used. A GaP (red) LED or a GaAs LED can be used as the light emitting element 111 that emits light with such a wavelength. Furthermore, it is more preferable to use light having a wavelength of 400 nm or more and 650 nm or less that is easily absorbed by hemoglobin in blood as the irradiation light A. A GaP (green) LED or a GaAsP LED can be used as the light emitting element 111 that emits light at such a wavelength.

  The light receiving element 121 is a photoelectric converter that outputs the received scattered light B as a signal S. The light receiving element 121 receives the scattered light B in the cuff 11. The type of the light receiving element 121 is determined by the type of the light emitting element 111 that emits the irradiation light A. When a GaP (red) LED or a GaAs LED is used for the light emitting element 111, it is preferable to use a Si phototransistor for the light receiving element 121. Further, when a GaP (green) LED or a GaAsP LED is used for the light emitting element 111, it is preferable to use a blue sensitive photodiode for the light receiving element 121. The signal S photoelectrically converted from the scattered light B is a pulsation waveform having measurement information on the pulsation of the blood vessel of the subject.

  The elastic member 10 includes a light shielding part 10a and a light transmitting part 10b. The elastic member 10 covers the light emitting element 111, the light receiving element 121, and the light receiving element 122, and is in close contact with the outer frame of the housing 12a so as not to leak air. The telescopic member 10 swells with air sent from the air pipe 14 connected to the housing 12a, and compresses the portion to be measured of the subject. The light transmitting portion 10b is arranged so that the light emitting element 111 can irradiate the irradiation light A to the outside, and the light receiving element 121 can receive the scattered light B from the outside. The material of the elastic member 10 is not particularly limited, but the light shielding portion 10a is preferably a stretchable, durable and light shielding cloth or rubber, and the light transmitting portion 10b is a light permeable rubber or vinyl. It is desirable.

  In the blood pressure measurement device 901, the reflected light C is light that is a part of the irradiation light A reflected by the surface of the stretchable member 10 on the light emitting element 111 side. Since the cuff 11 vibrates due to disturbances such as the movement of the subject and pulse waves, the intensity of the reflected light C varies according to the vibration.

  The light receiving element 122 is a photoelectric converter that receives the reflected light C and outputs a signal N. The light receiving element 122 is installed in the housing 12a at a position where the reflected light C can be received in the cuff 11 and is covered by the light shielding portion 10a and the scattered light B is not directly incident. The type of the light receiving element 122 is determined by the type of the light emitting element 111 that emits the irradiation light A. When a GaP (red) LED or a GaAs LED is used for the light emitting element 111, it is preferable to use a Si phototransistor for the light receiving element 122. Further, when a GaP (green) LED or a GaAsP LED is used for the light emitting element 111, it is preferable to use a blue sensitive photodiode for the light receiving element 122. The signal N photoelectrically converted from the reflected light C is a waveform of the intensity change of the reflected light C due to disturbance such as the movement of the subject or a pulse wave, and the noise of the signal S photoelectrically converted from the scattered light B by the light receiving element 121. Has ingredients.

  The blood pressure measurement device 901 may further include a difference calculation unit 201. The difference calculation unit 201 is connected to the light receiving element 121 and the light receiving element 122, receives the signal S and the signal N, and calculates the difference between the signal S and the signal N. A differential input operational amplifier circuit (hereinafter, “differential input operational amplifier circuit” is abbreviated as “op-amp”) can be used as the difference calculation means 201. An operational amplifier has two input terminals, and amplifies and outputs a potential difference (voltage difference) between signals input to both terminals. Therefore, when the signal S and the signal N are input to the operational amplifier, the operational amplifier outputs the output signal O from which the potential difference between the signal S and the signal N, that is, the common signal and the common noise component included in the signal S and the signal N are removed. To do. In addition, in the calculation of the potential difference between the signal S and the signal N, the operational amplifier has an optimum ratio of the signal S and the signal N so that the common signal and the common noise component with the signal N can be effectively removed from the input signal S. Can be set.

  The blood pressure measurement device 901 may further include a light shielding unit 15. When the light receiving element 122 receives the scattered light B, the output signal N includes the component of the signal S. Therefore, the signal S is canceled by the calculation of the signal S and the signal N in the difference calculation means 201, and the component of the signal S included in the output signal O is reduced. Therefore, the light receiving element 122 prevents the light receiving element 122 from receiving the scattered light B by the light shielding means 15 and prevents the signal N output from the light receiving element 122 from including the component of the signal S. The light shielding means 15 is installed in the housing 12a so as to open the vicinity of the elastic member 10 from which a part of the irradiation light A is reflected. The light shielding means 15 is preferably a metal plate or plastic plate painted in black so as not to scatter the scattered light B within the cuff 11.

  The blood pressure measurement device 901 operates as follows. The blood pressure measurement device 901 is mounted so that the elastic member 10 is in contact with the measurement portion of the subject. When the supply of air is received by the air pipe 14, the expandable member 10 swells, compresses the portion to be measured of the subject, and stops the blood flow inside the subject. Thereafter, the light emitting element 111 irradiates the external subject with the irradiation light A through the translucent part 10b of the extendable member 10, and the air pipe 14 gradually exhausts the air inside the cuff 11 so as to subject the subject to the subject. Reduce the pressure that presses the measurement part. As the pressure for compressing the measured portion of the subject decreases, the blood flow inside the subject begins to flow, and the irradiation light A is scattered by the pulse wave of the blood vessel inside the subject to become scattered light B, and again the translucent portion 10b. And is received by the light receiving element 121. The light receiving element 121 outputs a signal S corresponding to the intensity of the scattered light B. On the other hand, all of the irradiation light A does not transmit to the outside of the cuff 11, and a part of the irradiation light A becomes reflected light C on the surface of the stretchable member 10 on the light emitting element 111 side and is received by the light receiving element 122. Here, since the scattered light B is shielded by the light shielding means 15, the light receiving element 122 does not receive the scattered light B. The light receiving element 122 outputs a signal N corresponding to the intensity of the reflected light C. The output signal S and the signal N are difference-calculated by the difference calculation means 201, and an output signal O having a pulsation waveform from which noise components due to disturbances such as motion and pulsation are removed is output. The pulse wave of the subject can be measured by analyzing the output signal O by a predetermined method. When the air supplied into the cuff 11 is exhausted, the blood pressure measurement device 901 ends the blood pressure measurement when the expansion / contraction member 10 no longer compresses the portion to be measured of the subject.

Therefore, the blood pressure measurement device 901 can always measure the pulse wave of the blood vessel of the subject with high accuracy and stability even if it cannot be completely fixed to the peripheral part of the subject.
(Embodiment 2)

FIG. 2 is a schematic view showing an embodiment of a blood pressure measurement device according to the second embodiment of the present invention.
In the blood pressure measurement device 902 according to the present embodiment, the same reference numerals as those used in FIG. 1 have the same configuration and the same function. The difference from the blood pressure measurement device 901 is a light emitting element 112 and a light receiving element 123.

  In the blood pressure measurement device 902 of the present embodiment shown in FIG. 2, the light emitting element 112 is installed in the housing 12a so that the irradiation light D can be irradiated toward the light shielding portion 10a. Although the kind of the light emitting element 112 is not particularly limited, a small and power-saving LED can be used.

  In the blood pressure measurement device 902, the reflected light C is light that is reflected from the surface of the stretchable member 10 on the light emitting element 112 side. Since the cuff 11 vibrates due to disturbances such as the movement of the subject and pulse waves, the intensity of the reflected light C varies according to the vibration.

  The light receiving element 123 is a photoelectric converter that receives the reflected light C and outputs a signal N. The light receiving element 123 is installed in the housing 12 a so that the reflected light C can be received in the cuff 11. The type of the light receiving element 123 is determined by the type of the light emitting element 112 that emits the irradiation light D, and when a GaP LED or GaAs LED is used for the light emitting element 112, it is preferable to use a photodiode and a phototransistor.

  The blood pressure measurement device 902 may further include a difference calculation unit 201.

  The blood pressure measurement device 902 may further include a light shielding unit 15.

  In the blood pressure measurement device 902, the wavelength of the irradiation light A irradiated by the light emitting element 111 may be different from the wavelength of the irradiation light D irradiated by the light emitting element 112. Two different wavelengths are used for the irradiation light A irradiated by the light emitting element 111 and the irradiation light D irradiated by the light emitting element 112, and the light receiving element 123 is set to receive only the reflected light C, that is, the wavelength of the irradiation light D. deep. Thereby, even when the scattered light B enters the light receiving element 123, the light receiving element 123 does not detect the scattered light B having a wavelength different from the wavelength of the reflected light C. Therefore, a signal due to light other than the reflected light C can be reduced from the signal N output from the light receiving element 123. As a result, the signal N can accurately extract noise components due to disturbances such as movement and pulsation of the subject. Further, the light receiving element 121 is set to receive only the scattered light B, that is, the wavelength of the irradiation light A. Accordingly, even when the reflected light C is incident on the light receiving element 121, the light receiving element 121 does not detect the reflected light C having a wavelength different from the wavelength of the scattered light B. Thereby, the signal S can reduce a signal caused by light other than the scattered light B. Light of various wavelengths can be used as light of two different wavelengths. For example, the light emitting element 111 has a GaP LED (green) with a wavelength of about 550 nm, the light receiving element 121 has a blue sensitive photodiode capable of receiving light with a wavelength of 550 nm, the light emitting element 112 has a wavelength of about 950 nm and the light receiving element 123 has a wavelength. A Si phototransistor combined with a visible light cut filter capable of receiving light at 950 nm can be used. Since light near 550 nm is used as the irradiation light A and light near 950 nm is used as the irradiation light D, crosstalk between the scattered light B and the reflected light C can be prevented. Even when light receiving elements in the same wavelength band are used, crosstalk between scattered light B and reflected light C can be prevented by combining a wavelength cut filter. For example, when a GaP LED (green) having a wavelength of about 550 nm is used for the light emitting element 111 and a GaP LED (red) having a wavelength of about 700 nm is used for the light emitting element 112, the light receiving element 121 includes a filter that cuts a wavelength of 600 nm or more. Further, by using a CdS photoconductive cell including a CdS photoconductive cell and a CdS photoconductive cell provided with a filter that cuts a wavelength of 600 nm or less in the light receiving element 123, crosstalk between the scattered light B and the reflected light C can be prevented.

  The operation of the blood pressure measurement device 902 of this embodiment will be described. In the blood pressure measurement device 902 according to the present embodiment, the same reference numerals as those used in FIG. 1 perform the same operations.

  The reflected light C of the blood pressure measurement device 902 of the present embodiment is such that a part of the irradiation light A emitted from the light emitting element 111 during the operation of the blood pressure measurement device 901 is a surface on the light emitting element 111 side of the expansion member 10. The irradiation light D emitted from the light emitting element 112 is not the light reflected by the light emitting element 112 but the light reflected by the surface of the elastic member 10 on the light emitting element 112 side.

  The light receiving element 123 of the blood pressure measurement device 902 of the present embodiment is used for receiving the reflected light C.

  Here, when a GaP-based LED (green) is used as the light-emitting element 111, a blue-sensitive photodiode is used as the light-receiving element 121, a GaAs-based LED is used as the light-emitting element 112, and a visible light cut filter is combined with the light-receiving element 123, The light emitting element 111 irradiates irradiation light A having a wavelength of 550 nm toward an external subject from the translucent portion 10b. On the other hand, the light emitting element 112 irradiates the extending member 10 with irradiation light D having a wavelength of 950 nm. The irradiation light A is scattered by the pulse wave of the blood vessel inside the subject to become scattered light B having a wavelength of 550 nm, and again passes through the light transmitting part 10b and is received by the light receiving element 121. The irradiation light D becomes reflected light C having a wavelength of 950 nm on the surface of the elastic member 10 on the light emitting element 111 side and is received by the light receiving element 123. Since the light receiving element 121 detects only light having a wavelength in the vicinity of 550 nm, the reflected light C having a wavelength of 950 nm is not detected, and the signal S can be reduced by a signal other than the scattered light B. Since the light receiving element 123 detects only light having a wavelength in the vicinity of 950 nm, the scattered light B having a wavelength of 550 nm is not detected, and the signal N can be reduced by a signal other than the reflected light C. The output signal S and the signal N are difference-calculated by the difference calculation means 201, and an output signal O having a pulsation waveform from which noise components due to disturbance such as movement of the subject and pulsation are removed is output. The pulse wave of the subject can be measured by analyzing the output signal O by a predetermined method.

Therefore, the blood pressure measurement device 902 can always measure the pulse wave of the blood vessel of the subject with high accuracy and stability even if it cannot be completely fixed to the peripheral part of the subject.
(Embodiment 3)

FIG. 3 is a schematic diagram showing an embodiment of a blood pressure measurement device according to an embodiment of the third invention of the present application.
In the blood pressure measurement device 903 according to the present embodiment, the same reference numerals as those used in FIG. 1 have the same configuration and the same function. The difference from the blood pressure measurement device 901 is the housing 12b and the light receiving element 124.

  In the blood pressure measurement device 903 according to the present embodiment shown in FIG. 3, the housing 12b is installed to face the telescopic member 10, and the housing 12a and the housing 12b are connected by an arm (not shown).

  The transmitted light E is generated when the irradiation light A is absorbed and transmitted by the pulse wave of the blood vessel in the subject. More specifically, the irradiation light A is absorbed and transmitted by the increase / decrease of blood in the measurement portion accompanying the pulsation of the blood vessel of the subject, that is, the increase / decrease of the amount of hemoglobin in the blood to become the transmitted light E. As the irradiation light A, light having a wavelength of 300 nm to 1500 nm can be used. A GaP (red) LED or a GaAs LED can be used as the light emitting element 111 that emits light with such a wavelength. Furthermore, it is more preferable to use light having a wavelength of 400 nm or more and 650 nm or less that is easily absorbed by hemoglobin in blood as the irradiation light A. A GaP (green) LED or a GaAsP LED can be used as the light emitting element 111 that emits light at such a wavelength.

  The light receiving element 124 is a photoelectric converter that outputs the received transmitted light E as a signal S. The light receiving element 124 is installed in the housing 12b so that the transmitted light E can be received. The type of the light receiving element 124 is determined by the type of the light emitting element 111 that emits the irradiation light A. When a GaP (red) LED or a GaAs LED is used for the light emitting element 111, it is preferable to use a Si phototransistor for the light receiving element 124. Further, when a GaP (green) LED or a GaAsP LED is used for the light emitting element 111, it is preferable to use a blue sensitive photodiode for the light receiving element 124.

  The blood pressure measurement device 903 may further include a difference calculation unit 201.

  The operation of the blood pressure measurement device 903 of this embodiment will be described. In the blood pressure measurement device 903 according to the present embodiment, the same reference numerals as those used in FIG. 1 perform the same operations.

  The blood pressure measurement device 903 of the present embodiment is attached to the subject such that the elastic member 10 is in contact with the measurement part of the subject and the measurement part of the subject is sandwiched between the elastic member 10 and the housing 12b.

  Irradiation light A emitted from the light emitting element 111 toward the light transmitting portion 10b passes through the subject and is received by the light receiving element 124 as transmitted light E, and the light receiving element 124 outputs a signal S.

  The output signal S and the signal N are difference-calculated by the difference calculation means 201, and an output signal O having a pulsation waveform from which noise components due to disturbance such as movement of the subject and pulsation are removed is output. The pulse wave of the subject can be measured by analyzing the output signal O by a predetermined method.

Therefore, the blood pressure measurement device 903 can constantly measure the pulse wave of the blood vessel of the subject with high accuracy even if it cannot be completely fixed to the peripheral portion of the subject.
(Embodiment 4)

FIG. 4 is a schematic diagram showing an embodiment of a blood pressure measurement device according to the fourth embodiment of the present invention.
In the blood pressure measurement device 904 according to the present embodiment, the same reference numerals as those used in FIGS. 1, 2, and 3 have the same configuration and the same function. The difference between the blood pressure measurement device 901, the blood pressure measurement device 902 and the blood pressure measurement device 903 is a light emitting element 113 and a light receiving element 125.

  In the blood pressure measurement device 904 of the present embodiment shown in FIG. 4, the light emitting element 113 is installed in the housing 12b and irradiates the subject with the irradiation light F.

  The transmitted light G is generated when the irradiation light F is absorbed and transmitted by the pulse wave of blood in the subject. Specifically, the irradiation light F is absorbed and transmitted by the increase / decrease of blood in the measurement portion accompanying the pulsation of the blood vessel of the subject, that is, the increase / decrease of the amount of hemoglobin in the blood, and becomes the transmitted light G. As the irradiation light F, light having a wavelength of 300 nm to 1500 nm can be used. A GaP (red) LED or a GaAs LED can be used as the light emitting element 113 that emits light with such a wavelength. Furthermore, it is more preferable to use light having a wavelength of 400 nm or more and 650 nm or less that is easily absorbed by hemoglobin in blood as the irradiation light F. A GaP (green) LED or a GaAsP LED can be used as the light emitting element 113 that emits light with such a wavelength.

  The light receiving element 125 is a photoelectric converter that receives the transmitted light G and outputs a signal S. The light receiving element 125 is installed in the housing 12a so as to receive the transmitted light G through the light transmitting portion 10b. The type of the light receiving element 125 is determined by the type of the light emitting element 113 that irradiates the irradiation light F. When a GaP (red) LED or a GaAs LED is used for the light emitting element 113, it is preferable to use a Si phototransistor for the light receiving element 125. Further, when a GaP (green) LED or a GaAsP LED is used for the light emitting element 113, it is preferable to use a blue sensitive photodiode for the light receiving element 125.

  The blood pressure measurement device 904 may further include a difference calculation unit 201.

  The blood pressure measurement device 904 may further include a light shielding unit 15.

  Also in the blood pressure measurement device 904, two different wavelengths may be used for the irradiation light F irradiated by the light emitting element 113 and the irradiation light D irradiated by the light emitting element 112. Light of various wavelengths can be used as light of two different wavelengths.

  The operation of the blood pressure measurement device 904 of this embodiment will be described. In the blood pressure measurement device 904 according to the present embodiment, the same reference numerals as those used in FIGS. 1, 2, and 3 perform the same operation.

  The blood pressure measurement device 904 of the present embodiment is attached to the subject in the same manner as the blood pressure measurement device 903 is attached to the subject. The light emitting element 113 emits the irradiation light F toward the subject. The irradiation light F is absorbed and transmitted by the pulse wave of the blood vessel inside the subject and is received by the light receiving element 125 as the transmitted light G through the light transmitting part 10b. The light receiving element 125 outputs a signal S corresponding to the intensity of the transmitted light G.

  Here, when a GaP-based LED (green) is used as the light-emitting element 113, a blue-sensitive photodiode is used as the light-receiving element 125, a GaAs-based LED is used as the light-emitting element 112, and a visible light cut filter is combined with the light-receiving element 123, The light emitting element 113 irradiates the subject with irradiation light F having a wavelength of 550 nm. On the other hand, the light emitting element 112 irradiates the extending member 10 with irradiation light D having a wavelength of 950 nm. The irradiation light F becomes transmitted light G having a wavelength of 550 nm due to the pulse wave of the blood vessel inside the subject, passes through the light transmitting part 10b, and is received by the light receiving element 125. The irradiation light D becomes reflected light C having a wavelength of 950 nm on the light emitting element 112 side of the elastic member 10 and is received by the light receiving element 123. Since the light receiving element 125 detects only light having a wavelength in the vicinity of 550 nm, the reflected light C having a wavelength of 950 nm is not detected, and the signal S can be reduced by a signal other than the transmitted light G. Since the light receiving element 123 detects only light having a wavelength in the vicinity of 950 nm, the transmitted light G having a wavelength of 550 nm is not detected, and the signal N can be reduced by a signal other than the reflected light C. The output signal S and the signal N are difference-calculated by the difference calculation means 201, and an output signal O having a pulsation waveform from which noise components due to disturbance such as movement of the subject and pulsation are removed is output. The pulse wave of the subject can be measured by analyzing the output signal O by a predetermined method.

  Therefore, the blood pressure measurement device 904 can constantly measure the pulse wave of the blood vessel of the subject with high accuracy even if it cannot be completely fixed to the peripheral portion of the subject.

  The blood pressure measurement device of the present invention can be applied to a health appliance that detects biological information for health maintenance and medical examination.

It is a figure which shows the structure of the blood-pressure measuring apparatus 901 of embodiment which concerns on this invention. It is a figure which shows the structure of the blood-pressure measurement apparatus 902 of embodiment which concerns on this invention. It is a figure which shows the structure of the blood-pressure measurement apparatus 903 of embodiment which concerns on this invention. It is a figure which shows the structure of the blood-pressure measuring apparatus 904 of embodiment which concerns on this invention.

Explanation of symbols

901, 902, 903, 904 Blood pressure measuring device 10 Telescopic member 10a Light-shielding part 10b Light-transmitting part 11 Cuff 12a, 12b Housing 14 Air pipe 15 Light-shielding means 111, 112, 113 Light-emitting elements 121, 122, 123, 124, 125 Element 201 Difference calculation means A, D, F Irradiation light B Scattered light C Reflected light E G Transmitted light S, N Signal O Output signal

Claims (15)

A cuff partially covered with a light-transmitting elastic member,
A first light emitting element for irradiating light to the outside of the cuff through the light transmissive portion of the elastic member;
A first light receiving element that receives, in the cuff, light scattered outside from the light emitted by the first light emitting element through the light transmissive portion of the elastic member;
A second light-receiving element that receives light reflected by the surface of the elastic member on the first light-emitting element side in the cuff;
A blood pressure measurement device comprising:   The blood pressure measurement device according to claim 1, further comprising difference calculation means for calculating a difference between a signal output from the first light receiving element and a signal output from the second light receiving element.   3. The blood pressure measurement device according to claim 1, wherein the second light receiving element includes a light blocking unit that prevents light scattered outside from being received. 4. A cuff partially covered with a light-transmitting elastic member,
A first light emitting element for irradiating light to the outside of the cuff through the light transmissive portion of the elastic member;
A first light receiving element that receives, in the cuff, light scattered outside from the light emitted by the first light emitting element through the light transmissive portion of the elastic member;
A second light emitting element that emits light toward the elastic member in the cuff;
A third light receiving element that receives light reflected by the second light emitting element side surface of the telescopic member in the cuff;
A blood pressure measurement device comprising:   The blood pressure measurement device according to claim 4, further comprising a difference calculating means for calculating a difference between a signal output from the first light receiving element and a signal output from the third light receiving element.   The blood pressure measuring device according to claim 4 or 5, wherein the third light receiving element has a light shielding means for preventing the light scattered outside.   7. The blood pressure measurement device according to claim 4, wherein a wavelength of light emitted from the first light emitting element is different from a wavelength of light emitted from the second light emitting element. A cuff partially covered with a light-transmitting elastic member,
A first light emitting element for irradiating light to the outside of the cuff through the light transmissive portion of the elastic member;
A fourth light receiving element that receives light emitted from the first light emitting element outside the cuff through the light transmissive portion of the elastic member;
A second light receiving element that receives light reflected by the surface of the telescopic member on the first light emitting element side in the cuff;
A blood pressure measurement device comprising:   9. The blood pressure measurement device according to claim 8, further comprising difference calculation means for calculating a difference between a signal output from the fourth light receiving element and a signal output from the second light receiving element. A cuff partially covered with a light-transmitting elastic member,
A third light emitting element that emits light from outside the cuff;
A fifth light receiving element for receiving the light irradiated by the third light emitting element in the cuff through the light transmissive portion of the elastic member;
A second light emitting element that emits light toward the elastic member in the cuff;
A third light receiving element that receives light reflected by the second light emitting element side surface of the telescopic member in the cuff;
A blood pressure measurement device comprising:   The blood pressure measurement device according to claim 10, further comprising difference calculating means for calculating a difference between a signal output from the fifth light receiving element and a signal output from the third light receiving element.   The blood pressure measurement apparatus according to claim 10 or 11, wherein the third light receiving element includes a light shielding unit that prevents light received by the third light emitting element from being received.   The blood pressure measurement device according to claim 10, 11 or 12, wherein a wavelength of light emitted from the third light emitting element is different from a wavelength of light emitted from the second light emitting element.   The blood pressure measurement device according to any one of claims 1 to 7, wherein the blood pressure measurement device according to any one of claims 1 to 7 is attached to a part of the auricle and the irradiated light is scattered in the auricle outside the cuff. The blood pressure measurement device according to any one of claims 8 to 13, wherein the blood pressure measurement device is mounted on a part of the auricle and the irradiated light is transmitted through the auricle outside the cuff.

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